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New Montana T-rex and separate status for Nanotyrannus
From: Ben Creisler firstname.lastname@example.org
News story indicates a Montana T-rex find may support
separate status for Nanotyrannus:
T-rex roamed near Roundup: Fossil hunters stumbled across
bones 2 years ago
By ED KEMMICK
Of The Gazette Staff
One of the smallest and youngest Tyrannosaurus rex
skeletons ever found was discovered northeast of Roundup
and is being prepared at a new dinosaur museum in
Walter Stein, curator of the Rocky Mountain Dinosaur
Resource Center in Woodland Park, Colo., said he found the
fossil, dubbed "Sir William," on a ranch about 25 miles
from Roundup two years ago.
Stein said he and Mike Triebold, the owner and founder of
Triebold Paleontology Inc., for which Stein is the field
collections manager, had just received permission to look
for fossils on the ranch and were on their first visit in
late July 2002. Stein said it was blazing hot and they
were scouting out likely dig sites they could come back
to "when it was a little cooler."
They were interested mainly in what is known as the Bear
Paw shale formation, deposits of dark-gray to dark-brown
shale that are known to contain marine reptiles.
They hadn't gone far, he said, when "we saw this little
strip of Hell Creek out in the middle of nowhere." The
Hell Creek formation, which sits above the Bear Paw, dates
from the end of the dinosaur period, the late Cretaceous,
67 million to 65 million years ago.
Despite the heat, they got out to take a look, and within
half an hour Stein "stumbled across" a specimen that had
weathered out of a hillside. It proved to be a piece of
the young T-rex. After two years of "intense field
collection," Stein said, they are ready to announce their
He said they waited this long because they wanted to be
sure what they had and because last year they were
preoccupied with building their new museum, which barely
opened as scheduled last Memorial Day.
Stein said the T-rex found near Roundup was estimated to
be about 15 years old when it died. It was about 20 feet
long and weighed about 3,500 pounds, considerably smaller
than the average 6-ton adult T-rex.
Sir William was among 20 partial T-rex skeletons examined
by a team headed by Gregory Erickson of Florida State
University as part of a study of T-rex growth rates.
According to Stein, his find was the smallest and youngest
partial skeleton of the group, and is second in youth and
size only to a fossil represented by a skull fragment.
Only 35 or so partial T-rex skeletons have been collected
over the past 100 years, he said.
Erickson's study, the results of which were reported in
the journal Nature in August, showed that the T-rex "lived
fast and died young," as Erickson said in an Associated
Press story. He said the T-rex went into an explosive
growth spurt in its teen years, between 14 and 18, stopped
growing around age 20 apparently died at about 30.
Stein said Sir William, which he named after his 9-month-
old son, is important for several reasons. For one, it
supports the theory that a creature called the
Nannotyrannus is a separate genus of dinosaur, not merely
an immature T-rex, as some paleontologists have surmised.
Although the question is still open to debate, Stein said,
Sir William appears to differ markedly from Nannotyrannus
Examination of Sir William also is likely to advance
understanding of T-rex behavior, Stein said. Found around
the fossil were more than 50 Nannotyrannus teeth, which
may mean that the young T-rex was ambushed and killed by
the closely related dinosaurs. There is also some evidence
that another T-rex chewed on one of Sir William's bones.
If so, Stein said, it would be the first evidence of
cannibalism within Tyrannosaurs.
"This specimen's eventually going to tell us a whole lot
about T-rex behavior," Stein said.
Preparation of Sir William will take another one to two
years, Stein said, but it appears it will be between 30
and 50 percent complete and will include elements of the
skull, forelimbs, hind limbs, pelvis and backbone.